[PATCH v3 0/3] Add earlycon support for AMD Carrizo / Stoneyridge

[Daniel Kurtz]

AMD Carrizo / Stoneyridge use a DesignWare 8250 UART that uses a 48 MHz
input clock.  Currently, there is no way to tell earlycon to use a specific
uart input clock when configuring a baud rate.

Patch 1 adds an earlycon ->setup() callback to set up this clock.  The setup is
triggered on the commandline by specifying "earlycon=amdcz,...".

Patch 2 adds an ACPI SPCR quirk to automatically trigger this hook when the
ACPI SPCR table OEMID field is "AMDCZ ".

Patch 3 adds an additional fix which allows botht the ACPI SPCR quirk and amdcz
->setup() to tell 8250_core to skip initialization of old serial ports that do
not exist on these SoCs.

Daniel Kurtz (3):
  serial: 8250_early: Add earlycon support for AMD Carrizo / Stoneyridge
  ACPI: SPCR: Add support for AMD CT/SZ
  serial: core: Allow skipping old serial port initialization

 drivers/acpi/spcr.c                  | 26 ++++++++++++++++++++++++++
 drivers/tty/serial/8250/8250_core.c  |  6 ++++++
 drivers/tty/serial/8250/8250_early.c | 16 ++++++++++++++++
 include/linux/serial_8250.h          |  2 ++
 4 files changed, 50 insertions(+)

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2.16.2.804.g6dcf76e118-goog